Grade 18 (R56322) Titanium
Grade 18 titanium is a titanium alloy formulated for primary forming into wrought products. R56322 is the UNS number for this material. Additionally, the ASTM designation is Titanium Grade 18. It has a moderately high embodied energy among the wrought titaniums in the database.
The properties of grade 18 titanium include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare grade 18 titanium to: wrought titaniums (top), all titanium alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
110 GPa 15 x 106 psi
Elongation at Break
11 to 17 %
Fatigue Strength
330 to 480 MPa 49 to 69 x 103 psi
Poisson's Ratio
0.32
Reduction in Area
23 %
Shear Modulus
40 GPa 5.8 x 106 psi
Shear Strength
420 to 590 MPa 61 to 85 x 103 psi
Tensile Strength: Ultimate (UTS)
690 to 980 MPa 100 to 140 x 103 psi
Tensile Strength: Yield (Proof)
540 to 810 MPa 78 to 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
410 J/g
Maximum Temperature: Mechanical
330 °C 630 °F
Melting Completion (Liquidus)
1640 °C 2980 °F
Melting Onset (Solidus)
1590 °C 2890 °F
Specific Heat Capacity
550 J/kg-K 0.13 BTU/lb-°F
Thermal Conductivity
8.3 W/m-K 4.8 BTU/h-ft-°F
Thermal Expansion
9.9 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.7 % IACS
Otherwise Unclassified Properties
Density
4.5 g/cm3 280 lb/ft3
Embodied Carbon
41 kg CO2/kg material
Embodied Energy
670 MJ/kg 290 x 103 BTU/lb
Embodied Water
270 L/kg 33 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
87 to 110 MJ/m3
Resilience: Unit (Modulus of Resilience)
1380 to 3110 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
35 points
Strength to Weight: Axial
43 to 61 points
Strength to Weight: Bending
39 to 49 points
Thermal Diffusivity
3.4 mm2/s
Thermal Shock Resistance
47 to 67 points
Alloy Composition
| Ti | 92.5 to 95.5 | |
| Al | 2.5 to 3.5 | |
| V | 2.0 to 3.0 | |
| Fe | 0 to 0.25 | |
| O | 0 to 0.15 | |
| Pd | 0.040 to 0.080 | |
| C | 0 to 0.080 | |
| N | 0 to 0.030 | |
| H | 0 to 0.015 | |
| res. | 0 to 0.4 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B861: Standard Specification for Titanium and Titanium Alloy Seamless Pipe
ASTM B381: Standard Specification for Titanium and Titanium Alloy Forgings
ASTM B265: Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate
ASTM B348: Standard Specification for Titanium and Titanium Alloy Bars and Billets
Titanium and Titanium Alloys: Fundamentals and Applications, Christoph Leyens and Manfred Peters (editors), 2003
Titanium, 2nd ed., G. Lutjering and J. C. Williams, 2007
Aerospace Materials, Brian Cantor et al. (editors), 2001
Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.